Computing components and systems can be installed on circuit boards, cards, or trays. For example, the computing components may be installed on circuit boards that are connected to (e.g., plugged into) a backplane or installed in a rack or cabinet. A backplane can provide power to the circuit boards and communication between the computing components installed on the boards and other devices. In addition, a backplane system allows for circuit boards, and therefore computing components and systems, to be easily installed and replaced.
Hot swap controllers enable circuit boards to be installed and removed from a backplane without removing power from the backplane. For example, a hot swap controller may include circuitry that limits inrush currents to circuit boards when the circuit boards are inserted into a powered backplane. A hot swap controller may also protect circuit boards from abnormal voltage conditions, e.g., overvoltage or undervoltage conditions.